I ALWAYS recommend speaker design software to model the design & predict performance and to optimize box volume and port dimensions in a ported design. (The software will help you decide which is better.)
Everything is a trade-off!
Without doing any research on this particular driver & box...
In general, sealed designs then to roll-off more gently than ported designs. But you usually get more output from a ported design down to where it starts rolling-off, and it can start rolling-off at a lower frequency. So for example, the ported box might give you more output at 40Hz, but it rolls-off more quickly and the roll-off curves cross so the sealed box may be putting-out more at 20Hz. You can also tune the ported box with a little 1 or 2dB bump (or whatever) and extend-down the -3dB point a bit more.
Given a "small" box, a smaller driver will usually have a lower cut-off frequency (but less output capability).
Because of the more-gentle roll-off, it's easier to EQ & flatten a sealed box. If you want to go as low as possible, a sealed box with EQ, and a high-power amplifier and high-power driver is often the best way to go. You can also get-away with a smaller box if you can "overpower" it with EQ and wattage. In a home environment, you don't need a lot of efficiency. And since the roll-off is (usually) gentle & smooth you don't need fancy DSP EQ (ignoring room acoustics).
Pro subs used live and in dance clubs are usually highly efficiency ported designs that go-down to around 40Hz. It's the best compromise to fill a large space with bass you can feel. (Just for reference, the lowest-note on a standard bass guitar is about 42Hz.)
If you add a lot of low-end boost to a ported box, the driver tends to move freely-uncontrollably, with less sound-output at the lowest frequencies (because of that steeper roll-off) and the EQ just doesn't work as-well. You end-up wasting a lot of power and you are more likely to burn-out the speaker.
...My homemade subs are 15-inch drivers in large ported cabinets I think they tuned to around 30Hz, per the design software. I didn't measure them and I don't exactly remember, but they can "rattle the walls" and they put-out bass you can feel in your body.
Great explanation there!
My question about dance clubs is, if their subwoofers go as low as 40hz, how can they produce some Pop/Hip Hop songs that dig lower than that? And what about placing those subs inside -they can't just have one "seat" as a sweet spot, or even 1-2 rows where the bass is perfectly balanced-. They need to cover a big area with smooth bass response.
Also, I've read that even in the big i-Max cinema rooms with like 200+ seats, their subwoofers will only go down to 20hz (I guess that's the THX standard). Don't they care about producing the ULF effects or would it be to expensive to cover a huge cinema hall with subs that could dig down to 10-15hz?
